graft: use missing ancestors algorithm to find earlier grafts When the revisions to graft are numerically close to the destination, this avoids two walks up the DAG, which for a repository with over 470,000 changesets translates to around 2.2 seconds.

graft: find ancestors of destination lazily When the revisions to graft are numerically close to the destination, this avoids one walk up the DAG, which for a repository with over 470,000 changesets translates to around 1.1 seconds.

merge with crew

sslutil: try harder to avoid getpeercert problems We wrap both calls to getpeercert in a try/except to make sure we catch its bogus AttributeError.

copies._forwardcopies: use set operations to find missing files This is a performance win for a number of reasons: - We don't iterate over contexts, which avoids a completely unnecessary sorted call + the O(number of files) abstraction cost of doing that. - We don't check membership in a context, which avoids another O(number of files) abstraction cost. - We iterate over the manifests in C instead of Python. For a large repo with 170,000 files, this improves perfpathcopies from 0.34 seconds to 0.07. Anything that uses pathcopies, such as rebase or diff --git between two revisions, benefits.

perf: add a command to test copies.pathcopies perf An upcoming patch will improve the performance of this function, and this command will be used to demonstrate that improvement.

merge with stable